Water Resources & Pollution Chapters in Textbook: 9, 14Key Concepts:

Water availability ★ Only 3% of world’s water is fresh...and only 1% is available for use

Groundwater★ Unconfined Aquifers: ○ More likely to be contaminated by anthropogenic chemicals

○ Quicker to recharge (weeks-years)★ Confined Aquifers: ○ Concealed beneath impermeable rock, and therefore less likely to

be contaminated○ Slow to recharge because of the impermeable rock (10,000-20,000

years)○ May have an area near the surface the allows it to recharge (called a

recharge area). ○ Artesian Wells are wells that tap water from a confined aquifer. The

Confined aquifer is under a lot of pressure from the impermeable layer of rock above it that the water, when a well is created bursts out and is flowing. No pump is needed.

★ Problems with Overuse○ Salt Water Intrusion: Pumping water faster than it can recharge can harm water quality. Rapid

pumping near the coast can cause saltwater to displace the freshwater.

.

○ Cone of Depression:An area where there is no longer groundwater due to rapid pumping of a well.

★ Regulated by the Safe Drinking Water Act (which also regulates surface waters) ○ sets maximum contaminant levels in drinking water sources for 77 different substances.

Surface Waterpage 1

Water Resources & Pollution Chapters in Textbook: 9, 14

★ Water visible on the earth’s surface★ Regulated under the Clean Water Act of 1972

○ CWA was borne from the Federal Water Pollution Control Act of 1948

Water Diversion★ Levees and Dikes (New Orleans)★ Dams (Hoover and Three Gorges Dams)★ Aqueducts (Colorado River Aqueduct)

Desalination★ Distillation★ Reverse Osmosis★ Issues of brine disposal

Water Uses:

★ Agricultural○ Furrow (65% efficiency)○ flood (70% efficiency)○ Spray (75% efficiency)○ Drip (95% efficiency)

★ Industry○ genergating electricity○ cooling machinery○ refining paper

★ Household○ toilets○ lawn watering○ showers, sinks, pools

Conservation: What steps can you do to conserve water?★ Reuse Grey Water (using wastewater from sinks, showers and washing machine)★ Xeriscape the landscape by planting native to reduce need to water lawns

POLLUTIONWater Pollution: Any chemical, biological or physical change in water quality that has a harmful effect on living organisms (including humans!) or makes it unusable for agriculture

★ Point Sources - Discharge pollution from specific locations (single point). ○ EASY TO MONITOR/REGULATE○ Factories, power plants, oil wells

★ Non-Point Sources - Scattered or diffused, having no specific location of discharge. ○ HARDER TO CONTROL!!○ Agricultural fields, feedlots, golf courses

Major Water Pollutants★ Human wastewater

○ Excess nutrients (N & P) eutrophication➔○ Biological Oxygen Demand: amount of oxygen a

quality of water uses over a periods of time at a specific temperature

■ low BOD: less polluted by wastewater■high BOD means less oxygen available to

other organisms (can create Dead Zones)○ Disease-causing organisms (esp. Fecal coliform, a

mostly harmless group of bacteria, is an indicator species. It could indicate that the water is polluted with harmful bacteria such as E. Coli & Cholera)

page 2

Water Resources & Pollution Chapters in Textbook: 9, 14

★ Metals (Pb, Hg, As, Cd)

★ Acid (Acid mine drainage)

★ Synthetic Organics (pharma; pesticides; others)

★ Oil (Think about the effects of the Deepwater Horizon spill)

★ Solid Waste (especially plastic!)

★ Sediment (runoff from construction is a common cause of sediment pollution)

★ Thermal (often from nuclear power plants)

★ Noise pollution (underwater war ships training)

Wastewater Treatment (see your video worksheet from class)★ Septic System

○ Sewage enters septic tank, where floating materials will form a scum layer along the top, solids will settle onto the bottom and bacteria will break the sludge down and the liquid portion (septage) moves to the drain field, where will will slowly sink into the ground.

★ Sewage System○ Primary Treatment

■ solid waste removal○ Secondary Treatment

■ biological treatment in which bacteria break down organic material, converting it into CO2 and inorganic nutrients (such as nitrogen and phosphorus)

■ Final step in secondary treatment is UV radiation or Chlorine to kill any remaining pathogens.

○ Tertiary Treatment■ Uncommon….it is the final step of removal of nutrients (NPK)

Case Studies:Three Gorges Dam on the Yangtze River in China is the largest dam in the world. It can generate 85 billion kWh per year (11% of China’s electricity). It is over a mile wide, 600 feet tall, and its reservoir is 410 miles long.

page 3

Water Resources & Pollution Chapters in Textbook: 9, 14

They began construction on the dam in 1993 and completed the dam in 2006. In the process, over 1.3 million people were displaced. It disrupts the natural migration of fish and river dolphins. Fish ladders have alleviated the problem with fish by allowing them to swim upstream from the dam.

Colorado River fed by snowmelt in the Rockies, flows through seven states and supplies much of the West Coast with freshwater. Along its path are 14 major dams, and many aqueducts to help control flooding and supply cities, and rural areas with electricity and water. The Colorado River Aqueduct supplies all of Los Angeles. SWo much of the water is diverted and used that very little of this water reaches the end of its natural path--the Gulf of California.

Minamata Bay in Japan had over 27 tons of mercury containing compounds dumped into it by a chemical company that was producing products of mercury. It was thought that mercury; a fairly inert chemical would not hurt the bay. Bacteria in the bay turned the mercury into methylmercury, which is highly toxic. Algae, zooplankton, fishes, etc. Bioaccumulation caused people to get very sick eating the fish from the Bay. Fifty two people were badly poisoned and 17 died. To this day, mercury poisoning is called Minamata disease. It causes retardation in children, kidney failure and nervous disorders. Too much mercury causes insanity.

Relevant FRQ’s:

1999 (1) - water quality tests2001 (4) - farm water pollution2002 (2) - Colorado River diversion2004 (1) - mercury & seafood2007 (1) - sewage treatment2008 (2) - Landfill leachate

2009 (3) - Colorado River & impacts of climate change on hydrology,coastal ecosystems2011 (2) - ocean acidification2014 (2) - sewer systems2015 (1) - Everglades

(3) - Oil Spills 2017 (1) - microbeads, plastic pollution, wastewater

(3) - effects of deforestation on water quality (4) - dams, water diversions

Vocabulary

Aquifer

Unconfined aquifer

Confined aquifer

Water table

Groundwater recharge

Floodplain

Oligotrophic lake

Mesotrophic lake

Eutrophic lake

page 4

Water Resources & Pollution Chapters in Textbook: 9, 14

Levee

Dike

Dam

Fish ladder

Aqueduct

Distillation

Reverse osmosis

Furrow irrigation

Flood irrigation

Spray irrigation

Drip irrigation

Hydroponics

Gray water

Point sources

Nonpoint sources

Wastewater

Biochemical oxygen demand (BOD)

Dead zones

Eutrophication

Septic tank

Leach field

Primary treatment

Secondary treatment

Tertiary treatment

Disinfection (Chlorine/UV)

page 5

Water Resources & Pollution Chapters in Textbook: 9, 14

Manure lagoon

Acid mine drainage

page 6